Borehole apparatus



Emmi@ Smm MES D ec. 4, 1962 D. F. sAURENMAN rAL 3,066,739

BOREHOLE APPARATUS 2 Sheets-Sheet 1 Filed Deo. 10, 1958 INVENTORS gagn( Dec. 4, 1962 D sAURl-:NMAN ErAL 3,066,739

BoREHoLE APPARATUS Filed Dec. l0, 1958 2 Sheets-Sheet 2 Wina/MM ATTORNEY United States Patent O 3,066,739 BOREHDLE APPARATUS Dean F. Saurenman and Ulrich E. Voetter, Houston, Tex., assignors to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Filed Dec. 10, 1958, Ser. No. 779,345 13 Claims. (Cl. 166-187) The present invention relates to borehole apparatus and, more particularly, to a new and improved pack-off device arranged to be passed through a string of tubing for use in the well bores below the tubing.

A common practice in oil well production operations, after the casing has been set in the borehole, is to set a string of tubing in the casing with its lower end disposed at a level just above a formation or series of formations from which connate fluid is to be produced. The portion of the annulus between the lower end of the tubing and the casing is often sealed by a packer so that, after the section of the casing opposite the formation of interest is perforated, connate uids may flow through the tubing to the surface of the earth and the Well is thus placed in production. lf a packer is not used, the tubing and casing are sealed relative to one another at the well heads which similarly permits iluids to flow through the tubing. Eventually, diagnostic and remedial operations may be necessary in a section of the casing below the packer; however, the relatively small diameter of tubing prevents the use of casing tools having large diameters. Hence, smalldiametered tools adapted to pass through the tubing yet capable of operation in the relatively large diameter casing are needed.

Diagnostic operations, for example, often require the use of a tiowmeter to study the well under dynamic conditions and a typical owmeter arrangement for such a purpose includes a packer which closes off the well bore so that iluid can be directed through a metering chamber. In present practice, the tubing string is withdrawn from the well so that the flowmeter may be introduced and used to measure the rate of ow at various depths in the well thereby to determine the effective fluid tlow relative to the various formations. Obviously, a great saving in both time and expenses would be afforded if the tlowmeter arrangement could be introduced through the tubing.

It is therefore an object of the present invention to provide a new and improved pack-off device, which has a small diameter to permit passage through tubing and which is extendable to the eiective inside diameter of the casing.

Another object of the present invention is to provide a new and improved packer element adapted to pass through tubing and which may be extended into contact with the sidewall of a well at a depth beyond the lower end of the tubing.

It is a further object of the present invention to provide a new and improved packer for use with a tlowmeter apparatus or the like which may be selectively operated at various depths in a well.

A still further object of the present invention is to provide a new and improved packer for use with a flowmeter apparatus provided with a ow measuring passageway adapted to be restricted when the packer element is in a retracted condition and unrestricted when the packer element is in an extended condition.

These and other objects of the present invention are accomplished by the provision of a tubular support having fluid passageways therein. An imperforate tubular packer element having a relatively low coeicient of expansion has its ends sealingly secured to a movable collar on the support and to the support, respectively. Receipt of tluid under pressure through a rst passageway connected to the interior of the packer element causes it to be displaced ice between a retracted condition of comparatively small effective diameter to an extended condition of comparatively large eiective diameter. Reduction of the tiuid pressure in the interior of the packer element permits the element to assume its retracted position again. Resilient means are provided to facilitate movement of the element to its retracted condition.

In accordance with another aspect of the invention in a retracted condition of the packer element, a metering passageway in a tiowmeter apparatus is restricted by a portion of the movable collar thereby to protect a ow measuring means in the owmetering apparatus against excessive luid flow while the tool is lowered through the tubing. In establishing the extended condition of the packer element, the movable collar is displaced to unblock the restricted passageway.

The novel features of the present invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram of a tool embodying the present invention shown disposed in a section of a cased well bore;

FIG. 2 is a simplified view in side elevation of a packer element constructed in accordance with the invention illustrated in an extended condition in a cased borehole;

FIG. 3 is a view of the packer element similar to the representation of FIG. 2, but illustrating the packer element in a retracted condition in a cased borehole;

FIG. 4 is a view in longitudinal cross section of an embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along the line in FIG. 4; and

FIG. 6 illustrates a pressure transducer suitable for use with apparatus incorporating the present invention.

In FlG. 1, earth formations 11 and 12 are shown traversed by a borehole 13 which may be provided with a tubing 15- extending downward from the ground surface through a casing 14. At the lower end of the tubing a conventional packing means 16 seals ot the annular space between the tubing 15 and casing 14. Suspended from the lower end of an electrical cable 17 is a llowmeter apparatus 18 in which the present invention is embodied. The cable 17 is wound on a conventional winch (not shown) at the surface of the earth so that the tiowmeter apparatus may be lowered and raised in the usual manner. A packer element 19 on the apparatus 18 is shown in an extended condition etectively closing the casing 14 to fluid ow; however, a ow measuring passageway 20 extends through a portion of the apparatus 18 between ports 21 in the lower end of the apparatus below the packer element 19 and an opening 22 above the packer element 19 so that iluid may flow only through the passageway 20 from either above or below the packer element 19. It Will be appreciated that the extended packer element 19 serves as a barrier only to fluid flow through the casing and hence does not need to supportflarge hydrostatic pressures. Another iiuid passageway 23 extends from the interior 24 of the packer element 19 to a iluid displacement mechanism 25 connected by yet another fluid passageway 26 to ports 2-7 located above the packer element. The construction and operation of the apparatus thus far described will become more apparent in the explanation to follow.

Conventional ow rate measuring means 28 in the flow measuring passageway 20 provide an electrical signal indicative of the rate of fluid flow therethrough. This information is relayed through the electrical cable 17 to the surface of the earth where an appropriate indicator or recorder (not shown) is located. Fluid flow from below the packer element 19 may be derived from formation 12 through perforations 29 in the casing and while only one level of perforations is shown, it will be readily apparent that other levels may also contribute to the fluid flow. Alternatively, if desired, the fluid flow could be directed from the tubing to the formation 12 as in a fluid drive well.

Turning now to the apparatus as shown in FIG. 4, packer element 19 is received over relatively thin-walled tubular portions 36 and 31 of upper and lower collars 32 and 33, respectively. Conventional clamps 34 and 35 secure and seal the element to the respective collars. The tubular portion 30 of upper collar 32 is slidably received by a tubular supporting mandrel or member 36, while an upper, relatively thin-walled, tubular extension sleeve 37 of collar 32 has an inner diameter larger than the outer diameter of the supporting mandrel 36 to form an annular space 38 therebetween. Surrounding supporting mandrel 36 within the annular space 38 is a tension spring 39 which has its lower end secured to the collar 32 and its upper end secured to an upper housing body 40. Housing body 40 has a blind bore 41 adapted to receive the upper end of support mandrel 36 which is suitably secured therein as, for example, by welding. Housing body 40 has a lower end portion 42 of a diameter slightly smaller than the inner diameter of sleeve 37 to receive and permit sliding movement of the sleeve portion of the collar thereon. The upper portion 43 of housing body 40 has a slightly larger diameter which is compatable with the outer diameter of sleeve 37. Upward movement of collar 32 is limited by the effective physical length of member 19 so that the upper extremity of extension sleeve 37 is always slightly below a shoulder 44 formed between upper and lower portions 43 and 42. Spring 39 is placed in both longitudinal and torsional stress before it is fixed in place so that collar 32 is biased upwardly and rotatively relative to housing body 40 so that a spiral twist is produced in the packer element serving to wrap it snugly about the mandrel 36 (see FIG. 3).

In FIG. 2, the packer element 19 which embodies one aspect of the present invention is shown in an extended condition wherein it has an effective diameter substantially equal to the diameter of the casing 14. The packer element 19 is essentially comprised of an imperforate tubular member having a relatively low percentage of elongation per unit stre-ss. The ends of the tubular packer element are pleated and gathered together and secured to the upper and lower collars 32 and 33, respectively, so that each end of the packer element therefore has a similar amount of material as is present at its center. This arrangement permits a balancing of the effects of strain on the material when the packer element is extended. In other words, the peripheral length of the material of the packer element taken along a central cross section in the plane designated A--A (FIG. 2) will be equal to the peripheral length of the material in the packer element taken along a central cross section in the plane designated -B. The packer element may be retracted from an extended condition to a condition of comparatively small effective diameter (FIG. 3) by movement of the collars 32 and 33 relative to one another. This movement is accompanied by relative rotation between the collars thereby to effect a spiral twist in the packer element to wrap the packer element snugly about the mandrel 36 as shown in FIG. 3.

It will be appreciated from the foregoing description that the above-described packer element is not subjected to forces sufllcient to stretch or force asunder the material elements comprising the structure of the packer element when extended and hence is unlikely to be ruptured or torn in the borehole yet is capable of extension from a relatively small effective diameter, say 111,56 to a diameter of, for example, 8" without incurring any appreciable strain in the material.

The packer element itself may be composed of a treated fabric, for example, a fabric woven of Dacron fibers impregnated with -a polymer of trifluorochloroethylene sold under the trademark Kel-F Latex by M. W. Kellogg Co. In general, the packer element should have excellent chemical resistance, high electrical resistance and exceptional resistance to wetting by water. It should also be able to conform to the sidewalls of the borehole. Imperforate plastic film materials, such as the product polyethylene terephthalate resin sold under the trademark Mylar by E. I. du Pont de Nemours and Co. could be employed. Similarly, a woven fabric could be lined with an imperforate film material to form a suitable packer element; in any event, the selected material for the packer element should have a relatively low percentage of elongation per unit stress so that stretching strains are minimized when the packer element is in extended condition. In other words, the material should not stretch easily. Also, the packer element should have good resistance to the chemical effects of borehole fluids.

Referring once again to FIG. 4, the upper end of a lower housing body 46 has blind bores 47 and 48 of different diameters to receive the lower end of support mandrel 36 and an outwardly directed flange 49. Flange 49 is seated on the shoulder formed by the bores 47 and 48 while the lower collar 33 is threadedly received in the upper end of bore 47 to lock the flange 49 of support mandrel 36 to the lower housing body 46.

The flow measuring passageway 20 through the supporting mandrel is provided by a tubular flow mandrel 50 that extends through the support mandrel 36. Flow mandrel 50 has its respective end portions received in the housing body 46 and lower housing body 46. To provide suflicient space for electrical conductors, the flow mandrel 50 is eccentrically positioned and suitably secured within support mandrel 36 lby a spacer 51 (FIG. 5) at the lower end of support mandrel 36 and an eccentrically disposed blind bore 52 in the lower end of housing body 40. Flow mandrel 50 also is fluidly connected by a passageway 53 in housing body 40 to the upper opening 22 while the lower end of flow mandrel 50 is received in a bore 54 of lower housing body 46 which opens to a flow chamber 55 to which the ports 21 in the bottom sub 46 are fluidly connected. Disposed in flow chamber 55 are upper and lower sets of stationary vanes 56, 57. Each set of stationary vanes may comprise, for example, four individual vanes. Each of the stationary vanes extend radially from the longitudinal axis of the apparatus at an angle of degrees from one another and lie in vertical planes. A rotatable member 58 having vanes of appropriate pitch is responsive to fluid flow and rotates at a rate dependent upon the velocity of fluid flow through the chamber 5S in a conventional manner. Electrical conductors 59 oonnected to conventional measuring means 60', such as an electrical generator, associated with the rotatable member 58 are suitably passed through the apparatus 18 to the electrical cable 17 and provides means for transmitting an electrical signal indicative of the rate of flow to the surface. Measuring means 60 may be suitably secured (not sh-own) in a conventional manner to the Vane set 56.

The hydraulic system which serves to move the packer element 19 from a retracted to an extended condition includes a filter chamber 60 in the upper end of housing body 40 opened to the exterior of the apparatus 18 by ports 27. A hollow, thin-walled, annular filter 61 composed, for example, of a porous steel is secured within the chamber 60 by a spacer member 62 and is in the path of any fluid flowing from ports 27 to the interior of the filter 61. An intermediate tubular sub 63 threadedly connected to the housing body 40 secures the spacer 62 and filter 61 within the housing body. On a base plate 64 secured to sub 63 is a reversible motor-pump assembly 65, a solenoid valve 66 and a pressure transducer 67. One 'opening of the pump casing of the pump portion of assembly 65 is tluidly connected to the interior of the lter chamber 66 by a tubular pipe 68 while the other opening of the pump casing is connected by a tubular pipe 69 to the solenoid valve 66. The solenoid valve 66 is liuidly connected to the pressure transducer 617 by a tubular pipe 7l) while a tubular pipe 71 extending from the pressure transducer 67 through the spacer 62 and filter chamber 60 iluidly connects the valve 66 and the transducer 67 to a fluid passageway 72 in housing -body 40. Passageway 72 opens into the space or chamber 73 between the outer surface of the ilow mandrel 50 and the inner surface of the support mandrel 36 and ports 74 in the support mandrel 36 open intro the interior 24 of the packer element 19. From the foregoing it will be appreciated that flow passageway as above described extends between ports 27 and the interior 24 of the packer element.

A pressure balancing system for the various elements in sub 63 includes an upper tubular sub '76 threadedly connected to sub 63 which receives a pressure balance housing 77 secured therein by abutment with one end of sub 63 and a retaining collar 78 threadedly received within sub 76. Balance housing 77 has stepped portions 79, of reduced diameter, the larger-diametered portion 79 receiving a tubular resilient and flexible member 8l constructed, for example, of neoprene and the smaller- (diametered portion 80 being ported to an internal bore `Q32. The interior of sub 63 and bore 82 are lluidly corntmunicable and contain a pressure fluid such as a relatively lincompressible oil. The resilient member 81 acts as a flexible wall portion for the enclosed pressure balancing fluid which permits a balance of pressure between the hydrostatic pressure of well fluid and the pressure balancing fluid enclosed in sub 63 to be obtained. Ports 83 in sub 76 permit well fluid to have access to the outer wall of the flexible member 81.

Extending through housing 76 is a multioonductor electrical cable 17a containing conductors which are electrically insulated from one another and suitably connecte'd with the various electrical components of the apparatus 18. Also, a monoconductor may achieve all the necessary electrical functions by means of commonlyaccepted electronic controls. Also, in accordance with well-known techniques, various portions of the apparatus are provided with sealing means such as O rings to prevent fluid leaks between the assembled portions.

The motor-pump assembly 65 may be of conventional design having a small electric motor connected to a suitable pump. The motor is preferably a reversible type so that fluid may be pumped in either direction through the pump casing.

Solenoid valve '66 may be of conventional design arranged with a fluid conduit therethrough and a closure member arranged to normally close the fluid conduit yet adapted to open the conduit when the solenoid coil is energized. The electrical circuit for energizing the solenoid coil is preferably connected with the electrical circuit for the motor so that when the motor circuit is actuated, the valve is opened and, of course, when the motor circuit is de-actuated, the valve returns to its normally closed position.

As best seen in FIG. 6, pressure transducer 67 has a fluid conduit 85 fluidly connected between tubular pipes 70, '71 and a pressure tubev 86 opening into a lluid sealed chamber 87 in a housing 8S so that the pressure of the iluid in the hydraulic system may be measured. The pressure measurement is obtained by a flexible bellows 89 having a piston head 9i) connected to a sliding rod 91 of a potentiometer 92. The bellows has its open end suitably secured to a ported wall member 93 so that the pressure uid within sub 63 is admitted through ports 94 in the' housing 3S to one side of the piston head 90 while conditioned well tiuid in fluid conduit has access to the other side of the piston head 90. Hence, a difference in pressure across the piston head permits movement thereof which may be calibrated in terms of pressure units by the potentiometer 92. A tension spring 95 between the potentiometer 92 and pist-on head 90 permits return of the piston head 90 when the pressure in conduit S5 is reduced.

In operation, the apparatus 18 is first lowered through the tubing 15 to the level of the casing at which the ow is to be measured. During the descent of the tool the spring 39 maintains collar 32 in its uppermost position and packer element 19 remains in the spiral condition shown in FIG. 3. At the same time, the sleeve 37 of the collar 32 remains in place over opening 22 to restrict the iluid tlow therethrough hence reducing the speed of the rotatable vane 53 so that it will not be damaged by excessive fluid li-ows due to the lowering of the tool through the tubing.` Also during descent and at all levels in the borehole, the pressure balancing fluid within sub 63 is equalized with respect to the hydrostatic pressure of well fluid at the level at which apparatus 18 may be, by action of the resilient wall member 3l.

At the selected level below the tubing at which flow rate is to be measured, the motor-pump assembly 65 is energized and simultaneously, solenoid valve 66 is opened so that a fluid communication path is opened between the well iiuid exterior to the apparatus and the interior of the packer element 19. More particularly, motor-pump assembly 65 draws the well fluid through housing ports 27 to the filter chamber 60, the filter 61 preventing solid matter in the fluid from entering lter chamber 60. From the filter chamber 66", iluid is drawn through pipe 68 into the pump casing of the pump of assembly 65. The fluid is then pumped under pressure through pipe 69, valve 66,

ipe 70, transducer 67, pipe 71, passageway 72, space 73 and ports 74 to the interior 24 .of the packer element 19. The packer element 19 under the influence of the higher fluid pressure within, as compared to the pressure outside, is caused to extend outwardly. Simultaneously, collar 32 is displaced relative to collar 33 in opposition to the bias of spring 39. Movement of oollar 32 also unblocks the restriction to opening 22 so that fluid may freely liow through the flow measuring passageway 20. Packer element 19 is thus displaced into engagent with the/'inner wall of casing 14 as shown in FIG. 2. When packer member 19 fully engages the casing wall, a rapid pressure build-up in the packer element occurs. This is measured by transducer 67 so that when the packer element 19 is fully extended the motor-pump assembly 65 may be shut off. The valve 66 is closed coincident with the shutting oit' of assembly 65 so that the fluid pathway to the packer element l19 is closed olf thus retaining the pressured fluid within the packer element. Since the casing 14 is effec- -tively closed to fluid flow, except for tlow passage 20,

flow rate measurements may be made in the manner described hereinbefore.

To retract the packer element 19, the motor-pump assembly 65 is operated in a reverse manner to pump the fluid from the interior of the packer element 19 out through the filter 61 to the exterior of the apparatus 18 through the same fluid path that was employed in extending the packer element. As the fluid pressure within the interior of the packer element 19 is reduced compared to the outside pressure, the spring 39 urges upper collar 32 away from lower collar 33 while simultaneously rotating the collar 32 so that the packer element 19 is retracted and wrapped snugly about the supporting mandrel 36 as shown in FIG. 3. The apparatus may then be located at another level and the above-described operation repeated or it may be removed from the well.

From the above description, it will be apparent that a support which may include sub 76, sub 63, upper housing body 40, mandrel 36, and lower housing body 46 is adapted to be suspended in a well bore. A packer element having a relatively low percentage of elongation per unit stress has its end portions connected to the support by collars 32, 33. Means which may include the pump 65 and connecting passageways in the support are provided to increase the fluid pressure in the packer element and extend the packer element. Relative rotational and longitudinal movement of the packer element may be obtained to retract the packer element by a spring 39 in conjunction with a slidable collar 32. Thus, it will be appreciated that a relatively large diameter packer element which is not subject to elastic strains can be reduced in size to pass through small diameter tubing by wrapping the packer about the support.

It will be apparent from the foregoing that while only upper collar 32 is illustrated as movable that both collars could be movably mounted on the supporting mandrel 36 and resiliently biased by springs secured to each of the collars. Further, a spiral guiding system between a collar and the supporting mandrel 36 could be employed to rotate the collar while a spring or other motive power, as, for example, an electrical motor, displaces the collar longitudinally.

While a particular embodiment of the present inven tion has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects, and therefore the aim in the appended claims is to cover all such changes and modifications as fall Within the true spirit and scope of this invention. Although an exemplary embodiment of the invention has been described as applied to a flow measurement in a cased well, obviously the invention has utility in other applications. For example, flow measurements vmay be made in open hole. Also, in operations other than flow rate measurements, a process embodying the present invention may be conveniently em ployed.

What is claimed is:

l. Apparatus for use in a borehole comprising: a support adapted to be lowered into the borehole and having a longitudinal axis; a tubular element of an imperforate, relatively flexible material having a relatively low percentage of elongation per unit stress connected to said support and including at least one portion movable between a Iretracted conditon of comparatively small eflfective diameter and an extended condition of a larger effective diameter on the order of the diameter of the borehole; means for selectively increasing the fluid pressure within said tubular element to a value higher than the fluid pressure `outside said tubular element thereby to displace said one portion of said tubular element from said retracted condition toward said extended condition and for selectively reducing said first-mentioned fluid pressure; and means independent of said tubular element for resiliently imparting relative movement to opposite end portions of said tubular element in a direction away from one another and for rotating said end portions relative to one another to displace said one portion of said tubular element from said extended condition toward said retracted condition while attaining a generally spiral configuration.

2. Apparatus `for use in a borehole comprising: a support adapted to be lowered into the borehole and having a longitudinal axis; a tubular element of an imperforate, relatively flexible material having a relatively low percentage of elongation per unit stress connected to said support and including at least one portion movable between a retracted condition of comparatively small effective diameter and an extended condition of a larger effective diameter on the order of the diameter of the borehole, said tubular element being closed so as to receive and retain a fluid; a pump system iluidly coupled to the interior of said tubular element and to the space on the exterior thereof and selectively operable to increase the fluid pressure within said tubular element to a value higher than the fluid pressure outside said tubular element thereby to displace said one portion of said tubular element from said retracted condition toward said extended condition and selectively operable to reduce said first-mentioned `fluid pressure; and mechanical means connected to opposite end portions of said tubular element for forcibly relatively displacing said end portions in a `direction away from one another and for rotating said end portions relative to one another thereby to displace said one portion of said tubular element from said extended condition toward said retracted condition while attaining a generally spiral configuration.

3. Apparatus for use in a borehole including a cylindrical support having a longitudinal axis; a tubular collar slidably mounted on said support; an imperforate tubular packer element having a Irelatively low percentage of elongation per unit stress, said element receiving a portion of said support and being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis which is less than the effective diameter of said apparatus and an extended condition vof comparatively large effective diameter relative to said longitudinal axis; means for sealingly securing the respective ends of said packer element to said collar and a portion of said support so that the space within said packer element is adapted to receive and retain a fluid; means independent of said packer element for resiliently connecting said collar to said support to resiliently bias said collar in one direction so that said packer element is normally held in a retracted condition on said support and for rotating said collar relative to said support when said collar is displaced relative to said support; and means for applying a fluid under pressure to the space between said Asupport and said packer element to effect movement of said packer element from said retracted condition toward said extended condition thereby to displace said collar against said bias and for subsequently reducing the fluid pressure within said space to permit said bias to displace said collar in said one direction and return said packer element to its retracted condition.

4. Apparatus for use in a borehole comprising: a cylindrical support including portions of reduced diameter spaced intermediate of its ends; a tubular collar slidably mounted on a first portion of reduced diameter; an imperforate tubular packer element having relatively loW percentage of elongation per unit stress received on said tubular collar and a second portion of reduced diameter, said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to the longitudinal axis of said support and an extended condition of comparatively large effective diameter relative to the longitudinal axis of said support; means independent of said packer element connected to said support and said collar to resiliently bias said collar in ya direction away from said second portion; means for sealingly securing the respective ends of said packer element to said collar and said second portion so that the space within said packer element is adapted to receive and retain a fluid; means for applying a fluid under pressure to the space within said packer element to effect movement thereof from ysaid retracted condition toward said extended condition thereby to displace said collar toward said second portion against said bias and for subsequently reducing the dluid pressure within said packer element to permit said bias to displace said collar away from said second portion and return said packer element to its retracted condition.

5. Apparatus adapted to be passed through a tubing for use with a flowmeter apparatus in a borehole comprising: a cylindrical support having portions of reduced diameters spaced intermediate of its ends; a tubular collar slidably mounted on a first portion of reduced diameter, said collar having a tubular extension rwith an inner diameter larger than the diameter of said first portion thereby forming an annular space therebetween and an outer diameter generally corresponding to the diameter of said cylindrical support, said tubular extension adapted to be received by a second portion of reduced diameter; mechanical means disposed in said annular space and connected to said support and said collar to resiliently bias said collar and tubular extension in one direction so that said tubular extension tends to enclose said second portion of reduced diameter; a packer element received on said tubular collar and a third portion of reduced diameter, said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to the longitudinal axis of said support and an extended condition of comparatively large effective diameter relative to the longitudinal axis of said support means; means for sealingly securing the respective ends of said packer element to said collar and said third portion so that the space within said packer element is adapted to receive and retain a fluid; a passageway through said support having one end thereof opening in said second portion of reduced diameter whereby said tubular extension is adapted to restrict fluid flow through said passageway; means for applying a fluid under pressure to the space within said packer element to eifect movement thereof from said retracted condition toward said extended condition thereby to displace said collar toward said third portion against said bias and unblock the restriction in said passageway and for subsequently reducing the iluid pressure within said packer element to permit said bias to displace said collar away from said third portion and return said packer element to its retracted condition thereby permitting said tubular extension to restrict said passageway.

6. Apparatus adapted to be passed through tubing for use with a owrneter apparatus in boreholes comprising: a cylindrical support having portions of reduced diameters spaced intermediate of its ends; a tubular collar slidably mounted on a first portion of reduced diameter, said collar having a tubular extension with an inner diameter larger than the diameter of said first portion thereby forming an annular space therebetween and an outer diameter generally corresponding to the diameter of said cylindrical support, said tubular extension adapted to be received by a second portion of reduced diameter; means disposed in said annular space and connected to said support and said collar to resiliently bias said tubular extension in one direction so that said tubular extension tends to enclose said second portion of reduced diameter; an imperforate tubular packer element having a relatively low percentage of elongation per unit stress received on said tubular collar and a third portion of reduced diameter, said packer element being adapted to be displaced between a retracted condition of comparatively small eiective diameter relative to the longitudinal axis of said support and an extended condition of comparatively large etective diameter relative to the longitudinal axis of said support; means for sealingly securing the respective ends of said packer element to said collar and said third portion so that the space within said packer element is adapted to receive and retain a fluid; a passageway through said support having one end thereof opening in said second portion of reduced diameter whereby said tubular extension is adapted to restrict iiuid flow through said passageway; means for applying a fluid under pressure to the space within said packer element to effect movement thereof from said retracted condition toward said extended condition thereby to displace said collar toward said third portion against said bias thereby unblocking the restriction in said passageway and for subsequently reducing the tluid pressure within said packer element to permit said bias to displace said collar away form said third portion and return said packer element to its retracted condition thereby permitting said tubular extension to restrict said passageway.

7. Apparatus adapted to be passed through a tubing for use in a borehole comprised of: a tubular support having a longitudinal axis; a pair of tubular collars received on said tubular support and arranged for relative sliding movement toward and away from one another; an imperforate tubular packer element having a relatively low percentage of elongation per unit stress received by said tubular support, said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis and an extended condition of comparatively large effective diameter relative to said longitudinal axis; means for sealingly securing the respective ends of said packer element to said collars so that the space within said packer element is adapted to receive and retain a fluid; means independent of said packer element connected to at least one of said collars to resiliently bias said one collar in a direction away from the other said collar so that said packer element is normally held in a retracted condition on said support and for rotating one of said collars relative to the other of said collars when said collars are displaced relative to one another; means for applying a uid under pressure to the space within said packer element to effect movement thereof from said retracted condition toward said extended condition thereby to displace said collars toward one another against said bias and for subsequently reducing the fluid pressure within said packer element to permit said bias to displace said collars away from one another and return said packer element to its retracted condition.

8. Apparatus adapted to be passed through a tubing for use in a -borehole comprised of: a tubular support having a longitudinal axis; a p-air of tubular collars received on said tubular support; an imperforate tubular packer element having a relatively low percentage of elongation per unit stress received by said support, said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis and an extended condition of comparatively large effective diameter relative to said longitudinal axis; means for sealingly securing the respective ends of said packer element to said collars so that the space within said packer element is adapted to receive and retain a fluid; means to secure one of said collars to said support; means independent of said packer element connected between said support and the other of said collars to resiliently bias said last-mentioned collar in a direction away from said first-mentioned collar so that said packer element is normally held in a retracted con-dition on said support and for rotating said last-mentioned collars relative to said first-mentioned collars when said collars are displaced relative to one another; means for applying a fluid under pressure to the space within said packer element to eiect movement thereof from said retracted condition toward said extended condition thereby to displace said collars toward one another againsty said bias and for subsequently reducing the uid pressure within said packer element to permit said bias to displace said collars away from one another and return said packer element to its retracted condition.

9. Apparatus adapted to be passed through a tubing foruse in a borehole comprised of: a support including a first tubular mandrel having a longitudinal axis; a tubular collar slidably received on said first tubular mandrel; an imperforate tubular packer element having a relatively low percentage of elongation per unit stress received by said first mandrel, said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis and an extended condition of comparatively large effective diameter relative to said longitudinal axis; means for sealingly securing the respective ends of said packer element to said collar and said tubular mandrel so that the space within said packer element is adapted to receive and retain a uid, said first mandrel having openings therein to uidly connect the interior of said first mandrel and the interior of said packer element; means resiliently connecting said collar to said first tubular mandrel to resiliently bias said one collar in one direction so that said packer element is normally held in a retracted condition on said first mandrel and for rotating said collar relative to said first tubular mandrel when said collar is displaced longitudinally relative to said tubular m-andrel; a second tubular flow mandrel of smaller diameter than said first mandrel received within said first-mentioned mandrel; means to enclose the space between said second flow mandrel and said first mandrel near the respective ends of said first mandrel; means for applying a fluid under pressure to the space between said second flow mandrel and said first mandrel to effect movement of said packer element from said retracted condition toward said extended condition thereby to displace said collar against said bias and for subsequently reducing the fluid pressure within said space to permit said bias to displace said collar in said one direction and return said packer element to its retracted condition.

10. Apparatus adapted to be passed through a tubing for use in a borehole comprised of: a support including a first tubular mandrel having a longitudinal axis and first and second housing bodies connected to respective ends of said first tubular mandrel; a tubular collar slidably received on said tubular mandrel; an imperforate tubular packer element having a relatively low percentage of elongation per unit stress received on a portion of said first mandrel, said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis and an extended condition of comparatively large effective diameter relative to said longitudinal axis; means for sealingly securing the respective ends of said packer element to said collar and one of said housing bodies so that the space within said packer element is adapted to receive and retain a fluid, said first m-andrel having openings therein to fluidly connect the interior of said first mandrel to the interior of said packer element; means resiliently connecting said collar to the other of said housing bodies to resiliently bias said collar in one direction so that said packer element is normally held in a retracted condition on said first mandrel and for rotating said collar relative to said first tubular mandrel when said collar is displaced relative to said first tubular mandrel; a second tubular flow mandrel of lesser diameter than said first mandrel received within said first mandrel and having end portions extending into said first and second housing bodies, each of said housing bodies having passageways fluidly connected between said second flow mandrel and the exterior of the respective housing bodies; means to enclose the space at each end of said second flow mandrel with respect to said first mandrel; means for applying a fluid under pressure to the space between said second flow mandrel and said first mandrel to effect movement of -said packer element from said retracted condition toward said extended condition thereby to displace said collar against said bias and for subsequently reducing the fluid pressure within said space to permit said bias to displace said collar in said one direction and return said packer element to its retracted condition.

=11. Apparatus adapted to be passed through a tubing for use in a borehole comprised of: a support including a first tubular mandrel having a longitudinal axis and first and second housing bodies connected to respective ends of said first tubular mandrel; an imperforate tubular packer member having a relatively low percentage of elongation per unit stress received by said first mandrel, ysaid packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis and an extended condition of comparatively large effective diameter relative to said longitudinal axis; a tubular collar slidably received on said first supporting mandrel; means for sealingly securing the respective ends of said packer element to said collar and one of said housing bodies so that the space within said packer element is adapted to receive and retain a fluid; means connected between said other housing body and said collar to resiliently bias said collar in a direction away from said one housing body so that said packer element is normally held in a retracted condition on said first mandrel and for rotating said collar relative to said one housing body when said collar is displaced relative to said one housing body so that said packer element is normally wrapped about said mandrel; a second tubular flow mandrel of lesser diameter than said first mandrel disposed within said first support mandrel and extending between said housing bodies, said housing bodies having passageways between the interior of said second flow mandrel and the exterior of said housing bodies to permit fluid circulation therethrough, and said first supporting mandrel having openings therein permitting fluid communication between the interior of said packer element and the interior of said first support mandrel; `means for applying a fluid under pressure to the space within said packer element to effect movement thereof from said retracted condition toward said extended condition thereby to displace said collar against said bias and for subsequently reducing the fluid pressure within said packer element to permit said bias to displace said collar in said one direction and return said packer element to its retracted condition, said last-mentioned means including a fluid passageway connected between said space within said packer element and the well fluid exterior of said apparatus and further including a pump in said passageway to pressure well fluid to said space.

12. Apparatus adapted to be passed through a tubing for use in a borehole comprised of: a support including a first tubular mandrel having a longitudinal axis and first and second housing bodies connected to respective ends of said first tubular mandrel; an imperforate tubular packer element having a relatively low percentage of elongation per unit stress received by said first mandrel, -said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis and an extended condition of comparatively large effective diameter relative to said longitudinal axis; a tubular collar slidably received on said first supporting mandrel; means for sealingly securing the respective ends of said packer element to said collar and one of said housing bodies so that the space within said packer element is adapted to receive and retain a fluid; means connected between said other housing body and said collar to resiliently bias said collar in a direction away from said one housing body so that said packer element is normally held in a retracted condition on said first mandrel and for rotating said collar relative to said one housing body when said collar is displaced relative to said one housing body so that said packer element is normally wrapped about said first mandrel; a second tubular flow mandrel of a lesser diameter than said first mandrel disposed within said first support mandrel and extending between said housing bodies, said housing bodies having passageways between the interior of said flow mandrel and the exterior of said housing members to permit fluid circulation therethrough, said first supporting mandrel having openings therein permitting fluid communication between the interior of said packer element and the interior of said first support mandrel, and said tubular collar having a portion arranged to restrict one of said openings when biased away from said one housing body and to unblock said last-mentioned opening when said collar is displaced toward said one housing body; and means for applying a fluid under pressure to the space within said packer element to effect movement thereof from said retracted condition toward said extended condition thereby to displace said collar against said bias and for subsequently reducing the fluid pressure within said packer element to permit said bias to displace said collar in said one direction and return said packer element to its retracted condition.

13. Apparatus adapted to be passed through a tubing for use with a owmeter apparatus in a borehole comprised of: a support including a tirst tubular mandrel having a longitudinal axis and rst and second housing bodies connected to respective ends of said first tubular mandrel; an imperforate tubular packer element having a relatively low percentage of elongation per unit stress received by said first mandrel, said packer element being adapted to be displaced between a retracted condition of comparatively small effective diameter relative to said longitudinal axis and an extended condition of comparatively large eective diameter relative to said longitudinal axis; a tubular collar slidably received on said iirst supporting mandrel; means for sealingly securing the respective ends of said packer element to said collar and one of said housing bodies so that the space within said packer element is adapted to receive and retain a uid; means connected between said other housing body and said collar to resiliently bias said collar in a direction away from said one housing body so that said packer element is normally held in a retracted condition on said iirst mandrel and for rotating said collar relative to said one housing body when said collar is displaced relative to said one housing body so that said packer element is normally wrapped about said mandrel; a second tubular flow mandrel of lesser diameter than said first mandrel *disposed within said rst mandrel and extending between having openings therein permitting fluid communication between the interior of said packer element and the interior of said iirst support mandrel, and said tubular collar having a portion arranged to restrict one of said openings when biased away from said one housing body and to unblock said last-mentioned opening when said collar is displaced toward said one housing body; means for applying a fluid under pressure to the space within said packer element to etlect movement thereof from said retracted condition toward said extended condition thereby to displace said collar against said bias and for subsequently reducing the uid pressure within said packer element to permit said bias to displace said collar in said one direction and return said packer element to its retracted condition, said last-mentioned means including a uid passageway connected between said space within said packer element and the well fluid exterior of said apparatus and further including a pump in said passageway to pressure well iluid to said space.

References Cited in the file of this patent UNITED STATES PATENTS 1,828,381 Schuyler Oct. 20, 1931 2,629,446 {F1-cling et al. Feb. 24, 1953 2,681,706 Pottorf June 22, 1954 2,779,192 Rumble et al. Jan. 29, 1957 2,783,646 Rumble Mar. 5, 1957 2,829,518 -Rurnble et al. Apr. 8, 1958 2,856,006 Buck et al. Oct. 14, 1958 2,922,478 Maly Jan. 26, 1960 2,935,615 'True May 3, 1960 2,942,666 True et al. June 28, 1960 

